Abstract: A compliant workpiece support assembly for a microrobotic apparatus for aligning three workpieces and welding them into an assembled package, includes a lower support assembly having a ball and socket joint with a polymer ball seat cast around the ball. The ball has a radial bore containing a lower collet axially movable in the bore to grip one of the workpieces. The other two workpieces are held in telescoping arrangement, respectively in inner and outer collets of an upper support assembly, the collets being disposed coaxially one within the other and respectively having camming housings for opening and closing the collets. The outer collet housing supports the entire upper support assembly and is axially driven so that when the outer collet bottoms on the outer workpiece the continued movement of the outer housing closes the collet to grip the workpiece. The inner collet is closed over the inner workpiece by a pneumatic piston.